AJP - Gastrointestinal and Liver Physiology, Vol 265, Issue 1 15-G20, Copyright © 1993 by American Physiological Society
Hepatic vein, hepatic parenchymal, and inferior vena caval mechanoreceptors with phrenic afferents
D. R. Kostreva and S. P. Pontus
Department of Anesthesiology, Medical College of Wisconsin, Children's Hospital of Wisconsin, Milwaukee.
Dogs were anesthetized with pentobarbital sodium and placed on
positive-pressure ventilation. The right phrenic nerve and/or its C5 branch
were prepared for afferent recording. The hepatic veins, hepatic
parenchyma, diaphragm, and inferior vena cava were studied for
mechanoreceptors using light pressure and stroking as the stimuli.
Mechanosensitive areas were found in the hepatic veins, hepatic parenchyma
of the right medial lobe, and inferior vena cava. The hepatic vein and
inferior vena caval receptors are located in the same 1- to 2-cm region as
the sphincters that are found in these vessels. This study presents the
first experimental evidence for the existence of hepatic vein receptors,
hepatic parenchymal receptors, and inferior vena caval mechanoreceptors
with phrenic afferents in the dog. These sensory areas of the circulation
may be involved in the neural control of venous return as well as mediating
changes in intrahepatic and portal venous blood pressure during normal
respiration.
